Synthetic indole-derived cannabinoids have become commonly used recreational drugs and continue to be abused despite their adverse consequences. As compounds that were identified early in the epidemic (e.g., naphthoylindoles) have become legally banned, new compounds have appeared on the drug market. Two tetramethylcyclopropyl ketone indoles, UR-144...
As cannabis use is more frequent in patients with psychosis than in the general population and is known to be a risk factor for psychosis, the question arises whether cannabis contributes to recently detected brain volume reductions in schizophrenic psychoses. This study is the first to investigate how cannabis use is related to the cingulum volume, a brain region involved in the pathogenesis...
Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here, we show that synaptic and cognitive impairments following repeated exposure to Δ(9)-tetrahydrocannabinol (Δ(9)-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids in...
Background and Purpose Many young people consume ecstasy as a recreational drug and often in combination with cannabis. In this study, we aimed to mimic human consumption patterns and investigated, in male and female animals, the long‐term effects of Δ 9 ‐tetrahydrocannabinol ( THC ) and 3,4‐methylenedioxymethamphetamine ( MDMA ) on diverse neuroinflammation and neurotoxic markers. Experimental...
Ecstasy is a drug that is usually consumed by young people at the weekends and frequently, in combination with cannabis. In the present study we have investigated the long-term effects of administering increasing doses of delta-9-tetrahydrocannabinol [THC; 2.5, 5, 10 mg/kg; i.p.] from postnatal day (pnd) 28 to 45, alone and/or in conjunction with 3,4-methylenedioxymethamphetamine [MDMA; two...
Cannabis is the most commonly used illicit drug in adolescence. Heavy use is associated with deficits on a broad range of cognitive functions and heavy use during adolescence may impact development of gray and white matter. To examine differences in intrinsic brain activity and connectivity associated with cannabis dependence in adolescence using whole-brain voxelwise approaches. Adolescents...
BACKGROUND AND PURPOSE: Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present study was designed to assess whether the impairing effects of Δ(9) -tetrahydrocannabinol (THC) in...
A web-based survey was used to consult the opinions of experienced drug users on matters related to drug harms. We identified a rare sample of 93 drug users with personal experience with 11 different illicit drugs that are widely used in the UK. Asked to assess the relative harms of these drugs, they ranked alcohol and tobacco as the most harmful, and three "Class A" drugs (MDMA, LSD, and...
Background: Mindfulness-based approaches may be effective treatments for substance use disorders (SUDs), but they have only been investigated for SUDs in the group setting. Methods: A novel 10-week individual mindfulness-based psychotherapy was provided weekly to participants. Tolerability and therapeutic feasibility were assessed by retention rates, incidence of adverse events or clinical...
Current treatments for addiction are frequently ineffective. Hallucinogenic therapy has been indicated as helpful for a range of substance use disorders, yet this approach remains understudied and publicly unavailable. It is nonetheless a promising treatment, which has significant, long-term beneficial effects with single doses and a profile characterized by general safety, low toxicity, and...
Cannabinoid receptor type 1 (CB1 ) antagonists have been developed for the treatment of obesity and associated risk factors. Surinabant is a high affinity CB1 antagonist in vitro. The aim of this study was to assess the magnitude of inhibition by surinabant of CNS effects and heart rate induced by Δ(9) -tetrahydrocannabinol (THC) in humans. This was a double-blind, placebo-controlled,...
Despite the widespread application of drug modelling in psychiatric research, the relative value of different models has never been formally compared in the same analysis. Here we compared the effects of five drugs (cannabis, psilocybin, amphetamine, ketamine and alcohol) in relation to psychiatric symptoms in a two-part subjective analysis. In the first part, mental health professionals...
The potential therapeutic benefits of cannabinoid compounds have raised interest in understanding the molecular mechanisms that underlie cannabinoid-mediated effects. We previously showed that the acute amnesic-like effects of delta9-tetrahydrocannabinol (THC) were prevented by the subchronic inhibition of the mammalian target of rapamycin (mTOR) pathway. In the present study, we assess the...
Chronic cannabis use is associated with residual negative effects on measures of executive functioning. However, little previous work has focused specifically on executive processes involved in performance monitoring in frequent cannabis users. The present study investigated event-related potential (ERP) correlates of performance monitoring in chronic cannabis users. The error-related...
This form of ayahuasca-assisted therapy appears to be associated with statistically significant improvements in several factors related to problematic substance use among a rural aboriginal population. These findings suggest participants may have experienced positive psychological and behavioral changes in response to this therapeutic approach, and that more rigorous research of...
BACKGROUND: Cannabis use has been reported to be associated with an earlier onset of symptoms in patients with first-episode psychosis, and a worse outcome in those who continue to take cannabis. In general, studies have concentrated on symptoms of psychosis rather than mania. In this study, using a longitudinal design in a large naturalistic cohort of patients with first-episode psychosis, we...
The role of cannabis in the etiology of schizophrenia has been documented as possibly the strongest environmental risk factor. However, the pathomechanism whereby cannabis use increases this risk has not yet been identified. We argue that this pathomechanism may involve direct effects of exogenous cannabinoids on T-type calcium channels in the thalamus. These channels are crucial for...
Marijuana (MJ) remains the most widely used illicit drug of abuse, and accordingly, is associated with adverse effects on mental and physical health, and neurocognitive decline. Studies investigating the neurobiology of underlying MJ effects have demonstrated structural and functional alterations in brain areas that contain moderate to high concentrations of cannabinoid (CB1) receptors and that...
Expansion of medical marijuana use in the US and the recently successful decriminalization of recreational marijuana in two States elevates interest in the specific cognitive effects of Δ(9)tetrahydrocannabinol (Δ(9)THC), the major psychoactive constituent of marijuana. Controlled laboratory studies in nonhuman primates provide mixed evidence for specific effects of Δ(9)THC in learning and...
Addiction BiologyMarch 2013Alain Dervaux, Marie-Chantal Bourdel, Xavier Laqueille et al.
Psychomotor performance has consistently been found to be altered in chronic cannabis users. Neurological soft signs (NSS) reflect neurological dysfunction involving integrative networks, especially those involving the cerebellum, where cannabinoid receptors are particularly concentrated. Our objective was to study, for the first time, NSS in a group of patients with cannabis dependence...